1. Field of the Invention
The present invention relates to a power module comprising a plurality of switching elements connected in series, and in particular to a power module capable of reducing the radiation noise.
2. Background Art
In a power module, such as an inverter, a switching element, such as an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and a diode, is mounted. The size of the switching element is increased or decreased corresponding to the required capacity. When the capacity is large, the element size is also increased. However, if the element size is extremely large, the yield is lowered, and the manufacturing becomes difficult. Therefore, there is a certain limitation in the largest element size. For this reason, if the capacity is insufficient with just one element, a plurality of elements are connected in series (for example, refer to Japanese Patent Application Laid-Open No. 08-195471).